While the rebuttal makes good points, it still misses what the law is really about and why it isn't a step in the right direction at all. It's about prosecuting small-time drug dealers. Except now anyone caught exceeding the above limits of personal use is a drug dealer. The limits are so arbitrary they're laughable. I mean 5 grams of pot could keep you high for days or just give you a bad head ache, 40 mg of mdma? How much is that? the kid at the club only sells it by the pill.
TBF, it seems you could make yourself a pretty crazy personal party kit and stay under the legal limit. Too bad the kid caught with just a 10 mg bag of crappy pot will get a really hard time at the police station though.